so i pulled my 289 out yester day and tore it down. i was almost positive that it was original and had never been pulled out before. until, i start to pull the harmonic off, and someone had broken a bolt off in one of the puller holes. i said "oh crap someones been into this thing before" cause i knew the factory wouldnt have done that, plus, theres no need for the three holes when your installing it! after i got the pistons out, i pulled out the 'ol calipers, and its already been bored to 30 thousandths! im so pissed. for a 289, its not a good idea to go anything over .030 right???? cause itll run hot. can i still use my block if i just hone it? or should i ditch it and use my 302 block? i wanted to use my 289 cause im restoring to original and its a GT so i want the right block.

 

You should be able to go .040 without trouble, that's what my 302 is at, and I have no cooling problems.

 

If you're restoring a factory GT, I'd just push it to .040. If it wasn't a GT car, I'd say find another block. But someone down the road may want to buy a GT with a date code correct block

 

yeah it deffinately is a GT. 100% sure. so i guess i should keep the block. i work at a engine machine shop so i get all the machine work for free and all the parts at our cost. which is like 25-30% off everything.

 

Just go .040 over, worst case scenario it might need a larger radiator and/or a better water pump. I'm running a stock style 3 row radiator with a Milodon high volume water pump and have no heating issues, even in the summer. And it gets over 100* around here regularly.

 

.040 your fine, and hell even if there is a small little brow at the top of the cylinder you'll be fine

 

i thought the same thing about my 289, come to find out it had been bored .060 over

i guess we will find out if a 289 bored .060 over will get hot, i plan on a bigger aluminum radiator and a highvolume water pump

 

Dang i thought .040 over was pushing it

 

.040 is pushing it. SBF's use thin-wall castings, and core shift isn't uncommon, so boring any more than that tends to narrow the cylinder walls so much that you end up putting too much heat into the cooling system.

 

well everyone that has .040 over says its fine on theirs.